Filter element, dust collector, and methods

ABSTRACT

A filter element includes a media pack and a gasket member. The gasket member includes first and second gasket regions separated by a channel. The elements are usable in a dust collector having a dirty air inlet, a clean air outlet, and a tubesheet dividing between an unfiltered and a clean air volume. An element is removably mounted and sealed within the tube sheet. At least one projection angled relative to a plane of the tube sheet extends into the channel of the gasket member. A method of servicing a dust collector includes removing a first filter element from the tube sheet in the housing, and then sealing a second filter element against the tube sheet by orienting at least one projection extending from a plane of the tube sheet into a channel defined by a gasket member secured to the second filter element. An axial force is exerted to form a seal between the gasket member and the tube sheet.

This application is a Continuation of U.S. Ser. No. 12/936,079, filed 29Mar. 2011, which is a US National Stage of PCT International Patentapplication No. PCT/US2009/039531 filed 3 Apr. 2009 in the name ofDonaldson Company, Inc., a U.S. national corporation, applicant for thedesignation of all countries except the US, and Thomas D. Raether, BrianZauner, and Jim C. Rothman, all citizens of the U.S., applicants for thedesignation of the US only, and claims priority to U.S. Provisionalpatent application Serial Nos. 61/123,079, filed Apr. 4, 2008,61/079,959, filed Jul. 11, 2008, and 61/142,708, filed Jan. 6, 2009 andwhich applications are incorporated herein by reference. To the extentappropriate, a claim of priority is made to each of the above disclosedapplications.

TECHNICAL FIELD

This disclosure relates to filter elements, dust collectors, methods forpulse cleaning filter elements utilizing pressurized gas generators,methods of filtering, and methods of servicing. This disclosure alsorelates to apparatus including air cleaners, dust filters, and pulsecleaning technology.

BACKGROUND

Dust collectors include systems that take in unfiltered air, filter it,and exhaust clean air. Dust collectors are used in an variety ofenvironments, including factories, for example. These systems often haveone or more filter elements that are periodically changed out. Thesesystems also sometimes use pressurized gas to direct a pulse of gas(air) from the downstream side of the filter element to the upstreamside. This helps to remove some of the dust and debris collected on theupstream side of the filter element, which allows the filter element tobe used longer before the restriction becomes so high that it needs tobe changed. Examples of such air filters assemblies are disclosed in,for example, U.S. Pat. Nos. 6,090,173; 4,218,227; 4,395,269; 5,980,598;6,322,618; DE 3905113; and Patent Publication U.S. 2006/0112667A1, eachof these patent documents being incorporated by reference herein.Improvements in filter elements and dust collectors and methods aredesirable.

SUMMARY

A filter element is provided, including a media pack and a gasketmember. The gasket member includes first and second gasket regionsseparated by a channel.

One or more filter elements are usable in a dust collector. One exampledust collector includes a collector housing having a dirty air inlet, aclean air outlet, and a tube sheet dividing the housing between anunfiltered air volume and a clean air volume. At least one filterelement is removably mounted and sealed within the tube sheet. The atleast one filter element includes a media pack having first and secondopposite axial ends and a side extending between the first and secondaxial ends. A gasket member is adjacent to the side. The gasket memberincludes first and second gasket regions separated by a channel. Thefirst gasket region is nearer the media pack than the second gasketregion. The channel is an open volume between the first and secondgasket regions. At least one projection angled relative to a plane ofthe tube sheet and extends into the channel of the gasket member. An airdirection arrangement is constructed and arranged to draw air throughthe dirty air inlet, into the unfiltered air volume, through the filterelement, into the clean air volume, and then out through the clean airoutlet.

A method of servicing a dust collector includes removing a first filterelement from the tube sheet in the housing, and then sealing a secondfilter element against the tube sheet by orienting at least oneprojection extending from a plane of the tube sheet into a channeldefined by a gasket member secured to the second filter element. Next,an axial force is exerted against the gasket member to form a sealbetween the gasket member and the tube sheet.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view, partially broken away, of oneembodiment of an air filter system utilizing principles of thisdisclosure;

FIG. 2 is a schematic side elevational view illustrating principles ofthis disclosure;

FIG. 3 is a schematic diagram illustrating principles of thisdisclosure;

FIG. 4 is a schematic view of another embodiment of a dust collectorsystem utilizing principles of this disclosure;

FIG. 5 is a perspective view of an accumulator utilized with thearrangement of FIG. 4;

FIG. 6 is a schematic cross-sectional view of a portion of a filterelement and tube sheet, constructed in accordance with principles ofthis disclosure;

FIG. 7 is a drawing similar to FIG. 6, but showing another embodiment ofa tube sheet;

FIG. 8 is a drawing similar to FIGS. 6 and 7, but showing anotherembodiment of a tube sheet;

FIG. 9 is a side elevational view of a portion of the tube sheet of FIG.8;

FIG. 10 is a view similar to FIGS. 6-8, but showing another embodimentof a tube sheet;

FIG. 11 is a view similar to FIGS. 6-8 and 10, but showing anotherembodiment of a tube sheet;

FIG. 12 is a view similar to FIGS. 6-8, 10, and 11, but showing anotherembodiment of a tube sheet and also depicting a clamp;

FIG. 13 is a view similar to FIGS. 6-8 and 10-12, but showing anotherembodiment of a gasket member, tube sheet, and clamp;

FIG. 14 is a view similar to FIGS. 6-8 and 10-12, but showing anotherembodiment of a gasket member, tube sheet, and clamp;

FIGS. 15-17 are schematic, top plan views of filter elements that can beutilized with the system, in accordance with principles of thisdisclosure;

FIG. 18 is an exploded perspective of another embodiment of a dustcollector system utilizing principles of this disclosure;

FIG. 18A is a close-up perspective view of one of the openings in thetube sheet of the dust collector embodiment shown in FIG. 18.

FIG. 19 is a front elevational view of the dust collector of FIG. 18;

FIG. 20 is a cross-sectional view of the dust collector of FIGS. 18 and19, the cross-section being taken along the line A-A of FIG. 19;

FIG. 21 is a perspective of the cross-sectional view of FIG. 20;

FIG. 22 is a perspective view of an accumulator utilized with thearrangement of FIGS. 18-21;

FIG. 23 is another perspective view of the accumulator of FIG. 22;

FIG. 24 is a perspective, cross-sectional view of another embodiment ofa dust collector system utilizing principles of this disclosure, thecross-section being taken along the line A-A of FIG. 25;

FIG. 25 is a front elevational view of the dust collector system of FIG.24;

FIG. 26 is a cross-sectional view of the dust collector system of FIGS.24 and 25, the cross-section being taken along the line A-A of FIG. 25;

FIG. 27 is a schematic cross-sectional view of a filter element and tubesheet, constructed in accordance with the principles of this disclosureand as installed in a dust collector;

FIG. 28 is a schematic cross-sectional view of a portion of a filterelement and tube sheet of FIG. 27, constructed in accordance withprinciples of this disclosure;

FIG. 29 is a schematic, perspective view of another embodiment of afilter element removably secured within a filter retainer having anaccumulator, constructed according to principles of this disclosure;

FIG. 30 is an exploded perspective view of the arrangement of FIG. 29;

FIG. 31 is a perspective view of the retainer illustrated in FIGS. 29and 30;

FIG. 32 is a front plan view of the retainer of FIG. 31;

FIG. 33 is a side elevational view of the arrangement of FIG. 29;

FIG. 34 is a top plan view of the arrangement of FIG. 29;

FIG. 35 is a schematic, perspective view of another embodiment of afilter element held by a retainer having an accumulator, constructedaccording to principles of this disclosure;

FIG. 36 is an exploded perspective view of the arrangement of FIG. 35;

FIG. 37 is a perspective view of the filter retainer of FIGS. 35 and 36;

FIG. 38 is a front elevational view of the retainer of FIG. 37;

FIG. 39 is a side elevational view of the arrangement of FIG. 35; and

FIG. 40 is a top plan view of the arrangement of FIG. 35.

FIG. 41 is a schematic, top plan view of another embodiment of anaccumulator.

FIG. 42 is a schematic, cross-sectional view of the accumulator of FIG.41.

FIG. 43 is a schematic, top plan view of the accumulator of FIG. 41, butwithout a scoop section.

FIG. 44 is a schematic, cross-sectional view of the accumulator of FIG.41, but without a scoop section.

FIG. 45 is a schematic, top plan view of another embodiment of anaccumulator.

FIG. 45a is a bottom perspective view of the accumulator of FIG. 45.

FIG. 46 is a schematic, cross-sectional view of the accumulator of FIG.45.

FIG. 47 is a schematic, cross-sectional view of the accumulator of FIG.45 with the addition of lettered cross section identifiers.

FIG. 47a is a schematic, cross-sectional view of the accumulator of FIG.45 corresponding to section V-V shown on FIG. 45.

FIG. 47b is a schematic, cross-sectional view of the accumulator of FIG.45 corresponding to section W-W shown on FIG. 45.

FIG. 47c is a schematic, cross-sectional view of the accumulator of FIG.45 corresponding to section X-X shown on FIG. 45.

FIG. 47d is a schematic, cross-sectional view of the accumulator of FIG.45 corresponding to section Y-Y shown on FIG. 45.

FIG. 47e is a schematic, cross-sectional view of the accumulator of FIG.45 corresponding to section Z-Z shown on FIG. 45.

FIG. 47f is a schematic, cross-sectional view of the accumulator of FIG.45 corresponding to section AA-AA shown on FIG. 45.

FIG. 47g is a schematic, cross-sectional view of the accumulator of FIG.45 corresponding to section AB-AB shown on FIG. 45.

DETAILED DESCRIPTION

A. Example System of FIGS. 1-3

A dust collector, or air cleaner system, is depicted generally at 10 inFIG. 1. The system depicted includes a housing 12 having a side wallpanel 17 broken away to illustrate the arrangement of various portionsof the assembly. An upper wall panel 16 has an inner wall surface 19. Inthis embodiment, a dirty air inlet 20 is positioned in the upper wallpanel 16 so that the particulate-laden air or other fluid is introducedinto an unfiltered (dirty) fluid volume or chamber 22. The unfilteredvolume 22 is defined by an access door 13, the upper wall panel 16,opposing side wall panels 17, a tube sheet 28, and a bottom surface 23partially defining a collection area or hopper 25. The bottom base panelor frame 26 is secured to the side wall panels 17 in a suitable manner.

As mentioned above, the tube sheet 28 is mounted in the interior of thehousing 12. The tube sheet 28 includes a plurality of openings 30.Within each opening 30 is mounted an individual filter element, which inthe illustrated embodiment, is a panel-style filter element 32. By theterm “panel-style filter element” it is meant an element with filtermedia in which, in general, fluid to the filtered flows through thefilter element in a straight-flow thorough manner. For example, apanel-style filter element can be pleated media, depth media, flutedmedia, Z-media, or mini V-packs.

By “Z-media”, it is meant media having first and second opposite flowfaces with a plurality of flutes, each of the flutes having an upstreamportion adjacent to the first flow face and a downstream portionadjacent to second flow face, selected ones at the flutes being open atthe upstream portion and closed at the downstream portion, whileselected ones of the flutes are closed at the upstream portion and openat the downstream portion. The flutes open at the upstream end are“inlet flutes”, while the flutes open at the downstream end are “outletflutes.” The flutes can be straight, tapered, or darted. Examples offilter elements with Z-media are found in, for example, U.S. Pat. No.5,820,646; Patent Publication 2003/0121845; and U.S. Pat. No. 6,350,291,each of these patent documents being incorporated by reference herein.Depending on what type of panel-style filter element is selected, thedust collector housing 12 will have to be designed to accommodate thedifferences between the various types of panel-style media, includingfor example, differences in restriction, the volume of space occupied bythe media, and how the media needs to be sealed. It should be understoodthat the Z-media includes a media pack having opposite inlet and outletflow faces; the media pack comprising a plurality of flutes extending ina direction between the inlet flow face and the outlet flow face; themedia pack being closed to air entering the inlet flow face and passingoutwardly from the outlet flow face without filtering flow through mediaof the media pack.

The downstream sides of the filter elements are in communication with afiltered air volume 15. The filtered air is exhausted through a cleanair outlet 34. An air direction arrangement 35, which can be, forexample, a fan, blower, or bin-vent air direction arrangement 35 (shownschematically in hidden lines) operates to draw unfiltered air into theinlet 20 of the housing 12 and exhaust filtered air through the outlet34. While it is shown schematically at 35 within the housing 12, itshould be understood that the air direction arrangement 35 can belocated outside of the housing and be connected through suitable ductwork; or, in the case of a bin-vent, it is the construction of thehousing so that as a commodity is loaded into its holder and as it fillsup, the pressure builds up and then cause air to flow through thehousing 12.

In operation, fluid, such as air, to be filtered flows into the system10 through the inlet 20. From there, it flows through the filterelements 32. The filter elements 32 remove particulate material from thefluid. The filtered fluid then flows into the clean air volume orfiltered air volume or flow chamber 15. From there, the clean air flowsthrough an outlet 34.

Periodically, the filter elements 32 will be cleaned through a pulse jetsystem 37 by pulsing a fluid jet, such as a jet 39 (FIGS. 2-4) ofpressurized gas (e.g. air), from a downstream side 36 of the filterelement 32 to an upstream side 38 of the filter element 32.Specifically, jet 39 of pressurized gas will be directed throughindividual blow pipes 40, in preferred embodiments, a respective blowpipe 40 being oriented for each of the respective filter elements 32.This will direct the jet 39 through each filter element 32, from thedownstream side 36 to the upstream side 38. This helps to knock debrisand particulate from the upstream side 38 of the filter element 32,directing it off the filter element 32 and into a hopper.

A schematic illustration of the portion of the system 10 is illustratedin FIG. 2. In FIG. 2, the blow pipe 40 can be seen oriented with respectone the filter elements 32 in the opening 30 in the tube sheet 28. InFIG. 2, it can be seen how the blow pipe 40 is oriented relative to thefilter element 32 in a plane 60 (FIG. 3) that contains the respectiveopening 30 in the tube sheet 28 for the respective filter element 32,such that a pulse that comes from the blow pipe 40 is at an angle thatis not normal to a plane of the opening 30 and is not in line with ageneral direction of filtration flow thorough the filter element 32. Bythe term “not normal”, it is meant non-orthogonal, such as at an acuteor obtuse angle relative to the plane 60 that contains the opening 30for the respective filter element 32. By “not in line with a generaldirection of filtration flow”, it is meant, for a straight-through flowfilter, the pulse flow is in a direction that is not parallel to theflow of direction through the filter element 32. By directing the fluidpulse at the filter element 32 at such an angle 64, the exhaust jet,which expands at a predictable angle, creates a diameter D2 (FIG. 3)larger in one direction that a diameter D1 that is typically used in theprior art.

While the illustrated embodiment shows only a single blowpipe 40corresponding to a single filter element 32, it should be understoodthat in other implementations, there are more than one blowpipe 40 foreach element 32.

In some embodiments, at least a portion of the pulse can be trapped byusing an optional accumulator arrangement 42. The accumulatorarrangement 42 captures the flow of the pulse from the blow pipe 40. Inone embodiment of FIGS. 1 and 2, the accumulator arrangement 42 includesa least one plate, shown as first plate 44, oriented on the clean airside 15 of the tube sheet 28 and adjacent to the opening 30 of the tubesheet 28. Another embodiment of an accumulator arrangement is shown atreference numeral 232 in FIGS. 4 and 5, described below. Referring againto FIGS. 1 and 2, the first plate 44 may be any type of wall, sheetmetal, panel, baffle, rigid plastic, or generally non-porous solidstructure that is oriented to the adjacent respective opening in thetube sheet 28 for the respective filter element 32.

In embodiment of FIGS. 1 and 2, the accumulator arrangement includes asecond plate 46 oriented at an opposite end of the opening 30 at thetube sheet 28 from the first plate 44. In the embodiment shown, thefirst and second plates 44, 46 are aligned with the general direction ofthe pulse, but the angle does not necessarily need to be the same as theangle of the pulse direction. FIG. 2 illustrates a center line of thedirection of the pulse at 48. The first plate is mounted at a firstangle 50 relative to the tube sheet 28. The first angle is within about5° of center line 48 of a direction of the pulse. Similarly, the secondplate 46 is mounted at a second angle 52 relative to the tube sheet 28.The second angle 52 is within about 5° of the center line 48 of adirection of the pulse. In some embodiments, the first angle 50 and thesecond angle 52 are equal. In other embodiments, the first angle 50, andsecond angle 52 are unequal. In some embodiments, the first angle 50 andthe second angle 52 are within 30° of being parallel to each other. Theangles 50, 52 of the plates 44, 46 are selected based upon the angle 53of the pulse.

As illustrated in FIG. 2, the first plate 44 has length L₁, which ispreferably no longer than three times the length of the respectiveopening 30 in the tube sheet 28. This is because primary flow pressureloss increases with increase in length. Preferably, the length L₁ has alength that is between 25-75% of a length of the respective opening 30in the tube sheet 28. In preferred embodiments, the blowpipe 40 isspaced no more than 30-40 times of an inside diameter of the blowpipefrom the tube sheet to eject the pulse.

In FIG. 2, reference numeral 72 shows the offset between the pulsecenter line 48 and a center of the filter element 32. This shows how thecenter line 48 of the pulse is not always in alignment with the centerof the filter element 32.

In one embodiment, the plate that is closer to the respective blow pipe40 (in the embodiment illustrated, the second plate 46) has a lengththat is shorter than the other plate (in this example, the first plate44). In one embodiment, this shorter plate 46 has a length that is notless than 5% of a length of the respective opening 30 in the tube sheet28. This arrangement is advantageous because of both material savingsand pressure loss associated with pumping air flow.

Attention is directed to FIG. 3. In FIG. 3, the arrow 62 represents theprior art pulse direction. In the prior art, the standard pulsedirection is directed perpendicular or normal to the plane 60 thatcontains the tube sheet 28. Angle 64 shows the angle that is offset tothe vertical direction, or the direction from the standard, prior artdirection shown by arrow 62. A typical pulse expansion is shown at angle66, from the blow pipe 40. As explained above, the exhaust jet from theblow pipe 40 creates a diameter D2, covering a larger surface area inthe opening 30 of tube sheet 28, versus diameter D1 that comes from theexhaust jet shown at arrow 62 in the prior art arrangement.

One useful arrangement has the following angles and dimensions: Angle 64is 25°-35°, preferably 29°; angles 50 and 52 are equal and 18°-25°,preferably 22°-23°; first and second plates 44, 46 are parallel; offset72 is about 1 inch; length L1 is about 16-20 inches, preferably about18.75 inches; and length L2 is about 6-10 inches, preferably about 8.0inches.

B. Example System of FIG. 4

FIG. 4 depicts another embodiment of a dust collector 10′. In FIG. 4,useful embodiments for the filter element 32 are illustrated. Filterelement 32 includes a media pack 80 of Z-media, the definition ofZ-media as characterized above in Section A. The media pack 80 has firstand second opposite axial ends, or flow faces 81, 82, and a side (orside wall) 83 extending between the first and second flow faces 81, 82.In implementation, the first flow face 81 also corresponds to thedownstream flow face 36, while the second flow face 82 corresponds tothe upstream flow face 38.

In the embodiment shown, the media pack 80 includes a non-cylindricalpack of media that is a coiled construction 86. In alternativeembodiments, the media pack 80 can be a construction of stacked Z-media.The coiled construction 86 has an overall cross-sectional shape that canbe oval (FIG. 17) or race track-shaped (FIG. 15). In FIG. 15, the filterelement 32 is shown schematically in top plan, such that the downstreamflow face 81 is visible. In FIG. 15, it can be seen that in thisembodiment, the media pack 80 is race track-shaped in that it has a pairof straight parallel sides 88, 89 joined by rounded ends 90, 91. Inother embodiments, the media pack 80 can be round (FIG. 16) orrectangular, or rectangular with rounded corners.

In FIGS. 15-17, only a portion of the flow face 81 of the media pack 80is depicted schematically. It should be understood that the entire flowface 81 has filter media, but only the portion shown at referencenumeral 80 a is depicted in FIGS. 15-17.

C. Example Gasket Member of FIGS. 6-14

In reference now to FIGS. 6-14 and 27-28, the filter element 32 furtherincludes a gasket member 102. The gasket member 102 is adjacent to theside 83 of the media pack 80. In preferred implementations, the gasketmember 102 is secured to the side 83 and is molded directly to the side83 of the media pack 80. In other embodiments, the gasket member 102 canbe pre-made through, for example, an extrusion process and then attachedto the side 83 of the media pack 80 by glue or an adhesive.

In the embodiment of FIGS. 6-8, 10-12 and 27-28, the gasket member 102is identically structured, with the only difference between thesevarious figures being the tube sheet 28, or other structure relating tothe collector housing. These differences are further described below.Initially, the gasket member 102 depicted in FIGS. 6-8, 10-12 and 28-29are now described.

In the embodiment shown, the gasket member 102 includes a first gasketregion 130 and a second gasket region 132 separated by a channel 134.The first gasket region 130 is nearer the media pack 80 than the secondgasket region 132. In the embodiment shown, the first gasket region 130is secured directly against the media pack 80, while the second gasketregion 132 is remote from and radially spaced from the media pack 80.Example uses for the gasket member 102 including the channel 134 aredescribed below in Section E.

The first gasket region 130, in the embodiment shown, includes anattachment surface 138 secured to the side 83 of the media pack 80. Inthis particular embodiment, the first gasket region 130 has a firstchannel surface 140 angled from the attachment 138 in a direction towardthe second gasket region 132.

In the embodiment shown, the second gasket region 132 includes a secondchannel surface 142 angled in a direction toward the first gasket region130 and in a direction toward the first channel surface 140. Located inbetween the first channel surface 140 and the second channel surface 142is a base 144. Of course, the first and second channel surfaces 140 and142 can meet at an apex or point and not have base 144. This is merelyone example embodiment.

In the embodiment shown, the first channel surface 140, the secondchannel surface 142, and the base 144 define the channel 134. Thechannel 134 is an open volume between the first and second gasketregions 130, 132.

In the embodiment shown, the channel 134 has a length 145 of at least0.3 inch, for example, 0.4-0.6 inch. In the embodiment shown in FIG. 6,the length is measured from the end tip 146 of the second gasket region132 to the base 144, when the gasket member 102 is in an uncompressedstate. In the embodiment shown, the channel 134 has an average width ofabout 0.15 inch, as measured between the first and second gasket regions130, 132. For example, at the base 144, the channel 134 has a width ofabout 0.04-0.08 inch, for example about 0.06 inch, while the width ofthe channel 134 at its widest area, between end tip 146 of the secondgasket region 132 and a portion of the first gasket region 130 directlyhorizontal from tip 146, is at least 0.15 inch, for example about0.2-0.4 inch, typically about 0.25 inch.

In the embodiment shown, the second gasket region 132 further includesan outer angled surface 148. The outer angled surface 148, in theembodiment shown, is slanted in a direction from the tip 146 away fromthe second channel surface 142. As can be seen, in this embodiment, thesecond channel surface 142 and the outer surface 148 meet at an apex150, which is also the end tip 146. The outer angled surface 148generally slants in a direction from the apex 150 to a first axialgasket region 152. The first axial gasket region 152 is adjacent to thefirst axial end 81 of the media pack 80. Opposite of the first axialgasket region 152 is a second axial gasket region 154. The second axialgasket region defines the channel 134.

In the embodiment shown, the first axial gasket region 152 is a straightsurface 156. The straight surface 156 can be angled in a directiondownwardly and away from the media pack 80.

FIG. 13 illustrates an alternative embodiment of a gasket member 102′.The gasket member 102′ has many of the same features as gasket member102. For example, gasket member 102′ includes first gasket region 130,second gasket region 132, and a channel 134 separating the first gasketregion 130 and second gasket region 132. Other analogous features ofgasket member 102 include attachment surface 138, first channel surface140, second channel surface 142, base 144, tip 146, first axial gasketregion 152, and second axial gasket region 154.

In the embodiment of FIG. 13, the first axial gasket region 152 definesa second channel 160. The second channel 160 has an open volume. Thesecond channel 160 is defined by a first channel surface 162 that ispart of the first gasket region 130 and slopes from the straight surface156 downwardly and away from the first flow face 81 in a directiontoward the second gasket region 132. The second channel 160 is alsodefined by a second surface 164. The second channel surface 164 and thefirst channel surface 162 are joined by an intervening base 166. Thesecond channel surface 164 is angled upwardly and away from the base 166and away from the first gasket region 130.

In the embodiment of FIG. 13, the second gasket region 132 furtherincludes a first outer angled surface 168 extending from the end tip146, and a second outer angled surface 170 extending from the firstaxial gasket region 152. It should be noted that in FIG. 13, the firstaxial gasket region 152 is separated into two portions by the secondchannel surface 164. The second outer angled surface 170 extends fromthe first axial gasket region 152 that is located on the second gasketregion 132. The first outer angled surface 168 and the second outerangled surface 170 generally meet at an apex 172.

FIG. 14 illustrates another embodiment of gasket member 102″. Gasketmember 102″ is generally identical in structure to gasket member 102illustrated in FIGS. 6-8 and 10-12. As such, the gasket member 102″includes first gasket region 130, second gasket region 132, channel 134,attachment surface 138, first channel surface 140, second channelsurface 142, tip 146, outer angled surface 148, apex 150, first axialgasket region 152, second axial gasket region 154, and straight surface156.

In the embodiment of FIG. 14, the gasket member 102″ further includes aprotrusion-receiving hole 176. The hole 176 extends from the base 144 ofthe channel 134 all the way through to the first axial gasket region156. It should be understood that the through hole 176 will not be acontinuous hole all the way around the circumference of the filterelement 32, but only in one or more portions of the gasket member 102″.In addition, while the hole 176 in this embodiment is shown as goingcompletely through the gasket 102″, in other embodiments, the hole 176will be a blind hole that only goes partially through the gasket member102″. Example uses for the hole 176 are described below in Section E.

D. Some Problems with Existing Systems

As mentioned above, in preferred implementations, the dust collector 10and 10′ will utilize a system for pulse cleaning the filter elements 32.In existing systems, it can be a problem if the media in the elementsare not properly aligned with the pulse jet. If not aligned correctly,there will be less effective pulse cleaning done, and this results in ashorter filter life. Further, in existing systems, it can sometimes bedifficult to properly install the elements against the tube sheet to geta good reliable seal.

E. Example Solutions

It has been found that filter elements are pulse cleaned moreeffectively when the media packs 80 are in alignment with the generaldirection of the pulse. It is advantageous if one can ensure that thefilter elements 32 are properly installed in the collector housing 12such that the media pack 80 is aligned with the general direction of thepulse. In addition, it is desirable to have a system which encouragesthe proper installation of filter elements 32 within the housing 12. Itis desirable to properly install the filter elements 32 within thehousing 12 so that a good and functioning seal is created between thefilter element 32 and the tube sheet 28. Furthermore, it is desirable toincrease the ease and speed for installation of filter elements 32, suchthat proper servicing is maintained.

To achieve one or more of these benefits, the tube sheet 28 hasalignment structure 179 (FIG. 6) that cooperates with the gasket member102 in ways that will align the filter element 32 relative to the jet 39of the blowpipes 40 of the pulse cleaning; and will also encourage theproper sealing of the filter element 32 against the tube sheet 28.

Various embodiments of the tube sheet 28 are described below. In each ofthe embodiments, the tube sheet is shown as reference numeral 28, withthe differences being shown by new reference numerals.

1. Example Alignment Structure 179

In each of the embodiments of FIGS. 6-14, 27 and 28, there is an exampleof alignment structure 179 embodied as at least one projection 180angled relative to or above a plane 182 of the tube sheet 28. Inpreferred uses, the at least one projection 180 will extend from theplane 182 of the tube sheet 28 into the channel 134 of the gasket member102, 102′, 102″, which helps to ensure proper alignment of the filterelement 32 relative to the pulse jet 39. The projection 180 is notnecessarily a part of the tube sheet 28, although it can be. In theembodiment of FIGS. 12 and 13, for example, the projection 180 is a partof the filter support 184, which helps to hold the filter element 132.The projection 180 is positioned relative to the channel 134 in thegasket member 102, 102′, 102″ such that the filter element 32 will notbe properly oriented within the tube sheet 28 unless the projection 180is lined up to fit within the channel 134. This helps to ensure properlyalignment of the filter element 32 with the pulse jets 39.

In FIG. 6, the projection 180 is trapezoidal in shape as viewed from thecross-sectional side view of FIG. 6, including slanted wall 188 thatslants, in FIG. 6, at a generally same angle as the second channelsurface 142. In FIG. 6, the projection 180 further includes an oppositeslanted wall 189 which in the embodiment shown, slants at a generallysame angle as a first channel surface 140. The projection 180 can besolid, or it can have a through hole to save on material. In each ofthese embodiments, the projection 180 can include one or more throughholes extending therethrough to save on material and weight. In FIG. 6,the projection 180, when viewed from a front view, can have a variety ofshapes, including curved or rounded (see the example of FIG. 9, forinstance.)

In FIG. 7, the projection 180 is also trapezoidal in shape in thecross-section shown. In this embodiment, wall 192 and wall 194 aregenerally parallel. The wall 192 and wall 194 generally slope at thesame angle as the second channel surface 142.

In FIGS. 8, 27 and 28, the projection 180 is generally rectangular incross-section. FIG. 9 shows the projection 180 of FIG. 8 from a frontview. It can be seen how the projection 180 has a rounded outer profile202 but is viewed as rectangular in the view of FIG. 8. In FIG. 9, theprojection 180 has a through hole 204. It should be understood that ineach of the embodiments of FIGS. 6-8, 10-14 and 27-29, while thecross-sectional views of the projections 180 can show them astrapezoidal, rectangular, or triangular, the front views can havevarious profile shapes, such as rounded profile 202 as illustrated inFIG. 9.

In FIG. 10, the projection 180 is triangular in the cross-sectiondepicted with a rounded end 196.

In FIGS. 11-13, the projection 180 is an extension of the filter support184. In each of these embodiments, the projection 180 is generallyrectangular, in the cross-section shown.

In FIG. 14, the projection 180 is shown as an elongated rectangular bar198. The bar 198 extends through the hole 176. In embodiments where thehole 176 is only a blind hole and does not extend all the way through,then the bar 198 will be shorter and will only project up to the end ofthe hole 176.

The projection 180 can be embodied as a plurality of projections 180extending around the openings 30 (FIG. 1) of the tube sheet 28. Inaddition, in some embodiments, there may be only a single projection 180for selected ones of the openings 30 on the tube sheet 38.

In some example embodiments, the projection 180 extends into the channel134 at least 25% of the height of the channel 134. In many embodiments,the projection 180 extends between 30%-90%, inclusive, of the height ofthe channel 134.

2. Example Protrusions 210

In the embodiments of FIGS. 6-8, 11, and 12 there is further provided atleast one protrusion 210 extending at an angle (for example,perpendicular) to the plane 182 of the tube sheet 28 and being orientedlaterally adjacent to the second gasket region 132. The protrusion 210is not necessarily part of the tube sheet 28, although it can be. InFIG. 12, for example, the protrusion 210 is part of a clamp arrangement218.

In the embodiment of FIG. 6, the protrusion 210 is located so that thesecond gasket region 132 is trapped between the projection 180 and theprotrusion 210. In FIG. 6, the protrusion 210 has an angled wall 212that is generally parallel to and at the same angle as outer angledsurface 148. The protrusion 210 has a height greater than the height ofthe projection 180. In the embodiment of FIG. 6, this height is at leasttwice the height, and can be up to five times the height of theprojection 180. By locating and arranging the protrusion 210 at thislocation on the tube sheet 28 relative to the projection 180, it helpsthe person install the filter element 32 properly and quickly within thetube sheet 28. That is, there is a location gap 214 between theprojection 180 and the protrusion 210. This gap 214 is a convenient seatfor locating the second gasket region 132 when orienting the filterelement 32 in place.

In FIG. 7, the protrusion 210 is illustrated in the cross-sectional viewas being trapezoidal. In this embodiment, the protrusion 210 is abouthalf of the height of the second gasket region 132. In the embodiment ofFIG. 6, the protrusion 210 is at least 75% of the height of the secondgasket region 132.

In FIG. 8, the cross-sectional view of the protrusion 210 is shown asrectangular. In this embodiment, the protrusion 210 is taller than theprojection 180 but it is less than twice the length of the projection180. The protrusion 210 is between 30% and 60% of the height of thesecond gasket region 132.

In FIG. 10, the protrusion 210, in the cross-sectional elevational viewhas a triangular cross-section with a rounded end 216. In thisembodiment, the protrusion 210 is between 60% and 95% of the height ofthe second gasket region 132.

In FIG. 11, the protrusion 210 is similar in structure as the protrusion210 of FIG. 6.

In FIG. 12, the protrusion 210 is part of a clamp arrangement 218,described below.

3. Clamp Arrangement 218 and Further Example Protrusions

Attention is next directed to FIGS. 4 and 5. In general, the system 10′includes a clamp arrangement 218 to axially compress the gasket member102 to form a seal between and against the second gasket region 132 andthe tube sheet 28. The clamp arrangement 218 can be various types ofyokes, movable clamps, latches, etc. In the embodiment shown, the clamparrangement 218 is shown as part of a filter element retainer 220 (FIG.5). The retainer 220 includes a base plate 222 defining an opening 224.The opening 224 exposes one of the axial ends 81, 82 of the media pack80. In the embodiment shown, the opening 224 exposes the downstream end81 (FIG. 4).

A fastener arrangement 226 selectively connects the retainer 220 and thetube sheet 28. In the embodiment shown, the fastener arrangement 226includes a pair of thumb screws 228 extending through the base plate222. The screws 228 are received within the tube sheet 28. By tighteningthe thumb screws 228, an axial force is exerted against the base plate222 and the gasket member 102 to form a seal 230 (FIGS. 6-8 and 10-14)between and against the gasket member 102 and the tube sheet 28. Itshould be understood that the schematic drawings of FIGS. 6-8 and 10-14do not show the gasket member 102 compressed in the way it would appearwhen there is axial force to form the seal 230; rather, for purposes ofclarity, the gasket member 102 is shown in its uncompressed state.

In the embodiment of the retainer 220 that is depicted, the base plate222 includes tabs 250, 252 projecting therefrom. The tabs 250, 252engage with slots 254 (FIG. 4) in the tube sheet 28 to help hold theelements 32 in operable orientation.

Still in reference to FIG. 5, in this embodiment of the retainer 220,there is an accumulator 232. The accumulator 232 is oriented to retainthe pulse 39 of gas over the downstream axial end 81 of the media pack80. This can be seen in FIG. 4. In the embodiment of FIGS. 4 and 5, theaccumulator 232 includes a hood 234 secured to the base plate 222. Thehood 234 includes a wall 236 extending above the opening 234 in the baseplate 222. The wall 236 has an end 238 secured to the base plate 222.The wall 234 defines at an end 240 opposite of the end 238 an open mouth242. The mouth 242 receives the jet 39 of gas pulsed from the pulsingarrangement.

Also as can be seen in FIG. 5, in this embodiment, the retainer 220includes a bar 244 extending across the opening 224. The bar 244 helpsto prevent the filter elements 32 from falling through the opening 224.

Attention is again directed to the embodiment of FIG. 12. In FIG. 12, aportion of the filter retainer 220 is viewable. In this particularembodiment, the filter retainer 220 further includes protrusion 210,shown as extension 246. The extension 246 extends from the base plate222 in a direction toward the tube sheet 28. The extension 246 isoriented relative to the second gasket region 132 and the projection180, such that the second gasket region 132 is located between theprojection 180 and the extension 246. This extension 246 will help toensure proper placement of the filter element 32 and the retainer 220.

In FIG. 13, in this embodiment, the retainer 220 includes extensionmember 250. The extension member 250 extends into and is received by thesecond channel 160. As such, the second gasket region 132 is properlylocated against the tube sheet 28 by ensuring that the channel 134 andthe channel 160 receive the projection 180 and the extension member 250.In FIG. 13, the extension member 250 extends in a direction toward thetube sheet 28 from the base plate 222.

In FIG. 14, in this embodiment, the retainer 220 includes a slot or hole248 in at least a portion of the base plate 222. The hole 248 receivesthe bar 198 of the projection 180. This helps to precisely locate thefilter element 32 within its location against the tube sheet 28.

F. The Embodiment of FIGS. 18-23

FIGS. 18-23 depict another embodiment of a dust collector 310. In FIG.18, useful embodiments for the filter element 332 are illustrated.Filter element 332 includes a media pack 380 of Z-media, the definitionof Z-media as characterized above in Section A. The media pack 380 hasfirst and second opposite axial ends, or flow faces 381, 382, and a side(or side wall) 383 extending between the first and second flow faces381, 382. In implementation, the first flow face 381 also corresponds tothe downstream flow face 336, while the second flow face 382 correspondsto the upstream flow face 338.

In the embodiment shown, the media pack 380 includes a non-cylindricalpack of media that is a coiled construction 386. In alternativeembodiments, the media pack 380 can be a construction of stackedZ-media. The stacked construction or the coiled construction 386 canhave an overall cross-sectional shape that is oval (FIG. 17) or racetrack-shaped, and in the example shown in FIG. 18, the coiledconstruction 386 is race track-shaped. In the embodiment shown in FIG.18, the filter elements 332 further include optional handles 333. Thehandles 333 extend from the downstream flow face 336 and can be part ofa center core member, in which the media pack 380 is wound around (inthe case of a coiled element) or mounted within (in the case of astacked media element). The handles 333 can be shaped to define anopening sized to accommodate at least a portion of a human hand, so thatfingers may be placed between the downstream flow face 336 and a portionof the handle 333. Upon grasping of the handle 333, the element 332 canbe pulled from the opening 328 and removed from the housing 312.

In FIG. 18, the housing 312 defines a dirty air inlet 320, leading intoa dirty air chamber 322 (FIG. 19). A tube sheet 328 operably holds aplurality of filter elements 332, which are removably oriented therein.The tube sheet 328 separates the dirty air chamber 322 from a clean airvolume 315. There is a clean air outlet 334 and a air directionarrangement (not depicted) to direct air through the housing 312. Ahopper 335 collects dirt and debris that falls by gravity from thefilter elements 332. The housing 312 further includes a cover 313 thatdefines the clean air volume 315. The cover 313 mates with a body 317,the body 317 defining the dirty air chamber 322. The body 317, in theembodiment shown, is connected to the collection hopper 335. The cover313 holds blowpipes 340, which are used to pulse gas periodically at thedownstream flow face 336 in order to knock dirt and debris from theupstream side 338 of the filter elements 332 where it falls by gravityinto the hopper 335, as explained above.

The tube sheet 328 defines a plurality of openings 330, in which thefilter elements 332 are in intimate communication. In this embodiment,the filter elements 332 are arranged in two rows, 481, 482. For example,in the FIG. 18 embodiment, row 481 has 6 elements 332, while row 482 has6 elements. In the embodiment shown, each of the element 332 has arespective blowpipe 340 aimed at its downstream flow face 336. Thefilter elements 332 are sealed against the tube sheet 328 by compressionof gasket member 402 against the tube sheet 328. Refer also to FIG. 18Afor a close-up perspective view of the embodiment in FIG. 18. The tubesheet 328 can have alignment structure 179 that cooperates with gasket402, as discussed above and is incorporated by reference herein, inSection E.

The system 310 includes a clamp arrangement 418 to axially compress thegasket member 402 to form a seal between and against the gasket member402 and the tube sheet 328. The clamp arrangement 418 can be varioustypes of yokes, movable clamps, latches, etc. In the embodiment shown,the clamp arrangement 418 is shown as part of a filter element retainer420. The retainer 420 includes a base plate 422 defining an opening 424.The opening 424 exposes one of the axial ends 381, 382 of the media pack380. In the embodiment shown, the opening 424 exposes the downstream end381.

A fastener arrangement 426 selectively connects the retainer 420 and thetube sheet 328. In the embodiment shown, the fastener arrangement 426includes a pair of thumb screws 428 extending through the base plate422. The screws 428 are received within the tube sheet 328. Bytightening the thumb screws 428, an axial force is exerted against thebase plate 422 and the gasket member 402 to form a seal between andagainst the gasket member 402 and the tube sheet 328.

In the embodiment of the retainer 420 that is depicted, the base plate422 includes tabs 450, 452 projecting therefrom. The tabs 450, 452engage with slots 454 in the tube sheet 328 to help hold the elements332 in operable orientation.

In this embodiment of the retainer 420, there is an accumulator 432. Theaccumulator 432 is oriented to retain a pulse (such as pulse 39 in FIG.4) of gas over the downstream axial end 381 of the media pack 380. Inthe embodiment shown, the accumulator 432 includes a hood 434 secured tothe base plate 422. The hood 434 includes a wall 436 extending above theopening 434 in the base plate 422. The wall 436 has an end 438 securedto the base plate 422. The wall 434 defines at an end 440 opposite ofthe end 438 an open mouth 442. The mouth 442 receives the jet 39 of gaspulsed from the pulsing arrangement.

In the embodiment shown, the retainer 420 further includes a handle 421to assist in moving and manipulating the retainer 420. In thisembodiment, the handle 421 extends from the wall 436 and is sized toaccommodate at least a portion of a human hand between the handle 421and the wall 434. In use, the retainer may be lifted from the tube sheet328 by grasping the handle 421, which provides access to the respectivefilter element 332.

In this embodiment, the retainer 420 includes a bar 444 extending acrossthe opening 424. The bar 444 helps to prevent the filter elements 332from falling through the opening 424.

G. The Embodiment of FIGS. 24-26

In FIGS. 24-26, another embodiment of a dust collector is depicted at510. Dust collector 510 is analogous to collector 310, except that it ishalf of the size. Instead of having two rows 481, 482 of filter elements332, there is just a single row 483.

The dust collector 510 includes housing 512 having a body 517 and acover 513. The body 517 has with a dust collection hopper 525. The cover513 holds the gas pulse compressor having blow pipes 540 to emit pulses,as described above.

In FIGS. 24 and 26, retainers 520, each which may have a handle 521 canbe seen. The retainers help to hold and form a seal with elements 332,described above.

H. Methods

A method of servicing the dust collector 10, 10′, 310, 510 can bepracticed utilizing these arrangements. The following methods will makereference to the reference numerals used in the embodiments of FIGS.1-17, but it will be readily understood by those skilled in the art thatthese methods apply to the embodiments of FIGS. 18-26, as well. In suchmethods, a first filter element 32 is removed from the tube sheet 28 inthe housing 12. A second filter element 32 is provided. This secondfilter element 32 is sealed against the tube sheet 28 by orienting atleast one projection 180 extending relative to plane 182 of the tubesheet 28 into the channel 134 defined by the gasket member 102. Thegasket member 102 is secured to the filter element 32. An axial force isexerted against the gasket member 102 to form seal 230 between thegasket member 102 and the tube sheet 28. The step of sealing includesorienting the second filter element 32 to align the at least oneprojection 180 with the channel 134 defined by the gasket member 102such that the media pack 80 in the second filter element 32 is alignedfor receiving a pulse jet through a downstream side of the second filterelement 32.

The step of sealing can further include orienting the second filterelement 32 such that a portion of the gasket member 102 is orientedbetween the projection 180 and protrusion 210.

Methods of filtering include drawing air into the dust collector throughdirty air inlet 20, into an unfiltered air volume 22, through at leastone filter element 32 sealed against tube sheet 28, into the clean airvolume 15, and then out through the clean air outlet 34. The at leastone filter element 32 includes gasket member 102 forming the seal 230with the tube sheet 28. The gasket member 102 defines channel 134, andthere is projection 180 extending from the tube sheet 28 that isoriented within the channel 134.

I. The Embodiment of FIGS. 29-34

In FIGS. 29-34, another arrangement is depicted schematically at 600. Itshould be understood that arrangement 600 can be used in an appropriatesized and shaped dust collector, such as the collector 310. The methodsdescribed above can be used with this embodiment, as well as theembodiment of FIGS. 35-40. In FIG. 29, blow pipes 640 are shown inperspective view, but are depicted schematically. That is, the blowpipes 640, of course, would need to be connected to the dust collectorhousing. FIG. 29 depicts them schematically as they would be oriented atan angle relative to the assembly 601. The angle of the blow pipes 640relative to the filter element 632 downstream flow face 636 (FIG. 30)can be determined as described in connection with FIG. 2, above.

In FIGS. 29 and 30, filter element 632 can be seen. Filter element 632includes a media pack 680 of Z-media, the definition of Z-media ascharacterized in Section A. The media pack has first and second oppositeaxial ends or flow faces 681, 682 and a side (or side wall) 683,extending between the first and second flow faces 681, 682. Inimplementation, the first flow face 681 also corresponds to thedownstream flow face 636, while the second flow face 682 corresponds tothe upstream flow face 638.

In the embodiment shown, the media pack 680 includes a non-cylindricalsection of filter media that is rolled or otherwise formed into a coiledconstruction 686. In alternative embodiments, the media pack 680 can bea construction of stacked Z-media. The stacked construction or thecoiled construction 686 can have an overall cross-sectional shape thatis oval (FIG. 17) or racetrack shaped. In the example shown in FIG. 30,the coiled construction 686 is race-track shaped. Of course, in otherembodiments, the media pack 380 can be other shapes including round,rectangular with rounded corners, or other polygons.

In the embodiment shown in FIG. 30, the filter element 632 furtherincludes at least one optional handle 633. In the example of FIG. 30,there are two optional handles 633. The handles 633 are shown extendingfrom the downstream flow face 636 and may be part of a center coremember, in which the media pack 680 is wound around (in the case of acoiled element) or mounted within (in the case of a stacked mediaelement). The handle 633 can be shaped to define an opening sized toaccommodate a portion of a human hand, so that fingers may be placedbetween the downstream flow face 636 and a portion of the handle 633.Upon grasping the handle 633, the element 632 can be pulled from theopening 630 (FIG. 30) and removed from the assembly 601.

As with previous embodiments, the blow pipes 640 are used to pulse gasperiodically at the downstream flow face 636 in order to knock dirt anddebris from the upstream side 638 of the filter element 632.

In the embodiment of FIGS. 29-34, the arrangement 600 includes a holder604. The holder 604 is constructed for receiving and holding the filterelement 632 in place in the dust collector housing. In some embodiments,the holder 604 can be built in and be an integral part of the collectorhousing. In some embodiments, the holder 604 can be a separate piecewhich is then secured to the collector housing. In the embodiment shown,the holder 604 includes a member 606 defining surface 607. Inimplementation, the surface 607 functions as the tubesheet 608. In theembodiment shown, the member 606 forms a frame 610 defining an opening630. The filter element 632 is operably fitted within and removed fromthe holder 604 through the opening 630. In this embodiment, the frame610 defines a plurality of holes 612, which can receive screws or otherfasteners to secure the holder 604 to a remaining portion of the dustcollector housing.

The holder 604 includes alignment structure 614, such as alignmentstructure 179, discussed above, to cooperate a gasket 602 on the filterelement 632. In the embodiment shown in FIG. 30, the alignment structure614 includes a plurality of protrusions 616 extending axially from thesurface 607 of the member 606 and lining the perimeter of the opening630. These protrusions 616 cooperate with the gasket 602 as discussedabove and incorporated by reference herein in Section E.

Still in reference to FIG. 30, the holder 604 includes a pair of sidepanels 642 extending from the member 606 and along the perimeter of theopening 630. The side panels 642 help to hold the filter element 632along the side wall 633 of the element 632. In the embodiment shown, theside panels 642 generally extend the length of the side wall between thefirst flow face 681 and second flow face 682, when the filter element isoperably installed in the holder 604. The side panels 642 can defineopenings 644 for saving material cost or for creating a window such thatit is visible from the side whether the filter element 632 is installedwithin the holder 604.

Again, still in reference to FIG. 30, the holder 604 has an upwardlyextending flange 646 that axially protrudes from the surface 607 of themember 606. The flange 646 defines a slot arrangement 648 that is usedto engage with structure on the retainer 620, described further below.In this embodiment, the slot arrangement 648 includes a pair of slots649. Of course, other arrangements could be made.

Still in reference to FIG. 30, the holder 604, in this embodiment alsoincludes a bar arrangement 650 that is useful in supporting the filterelement 632 in place within the holder 644. The bar arrangement 650, inthis embodiment, includes at least one bar 651 and in the embodimentdepicted, two bars 651 that extend between the side panels 642. The bars651 contact the upstream flow face 638 of the filter element 632 whenthe filter element 632 is operably oriented within the holder 604.

A clamp arrangement 618 is provided to axially compress the gasketmember 602 to form a seal between and against the gasket member 602 andthe surface 607 of the member 606 of the holder 604. The clamparrangement 618 can be various types of yokes, movable clamps, latches,etc. In the embodiment shown, the clamp arrangement 618 is shown as partof the filter element retainer 620. The retainer 620 includes a baseplate 622 defining opening 624. The opening 624 exposes the downstreamflow face 636 of the media pack 680.

A fastener arrangement 626 selectively connects the retainer 620 and theholder 604. In the embodiment shown, the fastener arrangement 626includes a pair of thumb screws 628 extending through the base plate622. The screws 628 are received by the holder 604. In the embodiment ofFIG. 30, the holder 604 can include posts 652 for aligning with andreceiving the thumb screws 628. By tightening the thumb screws 628, anaxial force is exerted against the base plate 622, which squeezes thegasket member 602, which forms a seal between and against the gasket 602and the surface 607 of the member 606 of the holder 604. The surface 607is explained above, can be considered the same as the tube sheet 628.

In the embodiment of the retainer 620 that is depicted, the base plate622 includes tabs 654 projecting therefrom. The tabs 654 engage with theslots 649 in the flange 646 of the holder 604 to help hold the retainer620 and the filter element 622 in operable orientation.

In the filter retainer 620 illustrated in FIGS. 30 and 31, the retainer620 includes a gasket compression stop 623. The stop 623 projectsaxially from the base plate 622 in a direction opposite of the directionthat the hood 658 projects. The stop 623 will only allow the clamparrangement 618 to be secured to a certain point, such that the gasket602 is not overly squeezed or compressed. That is, the gasket 602 canonly be compressed by the base plate 622 due the thumb screws 628 untilthe stops 623 axially abut the surface 607, of the member 606. At thatpoint, interference between the stops 623 and the surface 607 will notpermit the thumb screws 628 to be tightened any further.

In this embodiment of the retainer 620, there is an accumulator 656. Theaccumulator 656 is oriented to retain a pulse of gas over the downstreamaxial end 681 of the media pack 680. In the embodiment shown, theaccumulator 656 includes a hood 658 secured to the base plate 622. Itshould be understood that by the term “secured to” it is meant that thebase plate 622 and the hood 658 can be made from the same piece ofmaterial and be formed and bent into the appropriate desired structure.It can also be secured to with fastening mechanisms such as welding.

In the embodiment shown, the hood 658 includes a wall 660 extendingaround the opening 624 and also extending above the opening 624. Thewall 660 has free end 662 defining an open mouth 664. The mouth 664receives the jet of gas pulsed from the pulsing arrangement emittedthrough the blow pipes 640.

In the embodiment shown, the wall 660 has a pair of end panels 666angled or slanted in a direction toward to opening 624 partially coverthe opening 624. Also in this arrangement, the wall 660 includes a pairof side panels 667 slanted toward to partially cover the opening 624.The side panels 667 can be angled relative to the base plate 622 basedupon the desired amount of accumulation. In the embodiment shown, theside panels 667 are angled relative to the base plate less than 90degrees and greater than 30 degrees, for example, 45-80 degrees. The endpanels 666, in the embodiment shown, are angled relative to the baseplate 622 more sharply than the side panels 667. In this embodiment, theend panels 666 are angled greater than 0 degrees and less than 60degrees, for example, 5-50 degrees.

In the embodiment shown, the side panels 667 also include handles 668.The handles 668 in this embodiment, are formed by openings in the sidepanels 667 that are sized to accommodate portions of a human hand. Inthis manner, the retainer 620 can be more easily grasped and manipulatedby user when servicing the dust collector.

The hood 658 is formed and arranged relative to the blow pipes 640 toretain the pulse of gas coming from the blow pipes 640. In otherembodiments, where the blow pipes 640 are arranged in differentorientations, it would be helpful to have the hood 658 formeddifferently. Such an example is shown in the embodiment of FIGS. 35-40,described below.

FIG. 34 illustrates schematically, the relative target pulse regions forthe blow pipes 640. Valve 1 targets the end 670 of the filter element632 that is opposite from the end which it is located. Valve 2 targetsthe end 671 which is at an end of filter element 632 opposite from whereit is located. The two valves 1, 2 together cover the entire downstreamflow face 636.

J. The Embodiment of FIGS. 35-40

Another embodiment of an arrangement is shown at 700 in FIGS. 35-40. Thearrangement 700 includes a filter and retainer assembly 701 and a pairof valves 703, 704. The valves 703, 704 each have a blow pipe 705 (ofFIG. 39). In this embodiment, the valves 703, 704 are arranged to beadjacent to the same end 706 of the filter element 632. The blow pipes705 are angled relative to the downstream flow face 636, according tothe description in connection with FIG. 2, above.

The assembly 701 includes the filter element 632 held by holder 604. Theholder 604 is depicted as being the same structure as in the embodimentof FIGS. 29-34, and the description of the holder 604 is incorporatedherein by reference. The filter element 632 is depicted as the samefilter element 632 in FIGS. 29-34, and the description is incorporatedherein by reference.

In the embodiment of FIGS. 35-40, analogous to the embodiment of FIGS.29-34, there is a retainer 710. In this embodiment, the retainer 710includes base plate 712, stop 713, tabs 714, opening 715, and anaccumulator 716.

The accumulator includes a hood 718 that is used to retain the pulsefrom the valves 703, 704. The hood 718 is constructed from a wall 720circumscribing the opening 715. In this embodiment, the wall 720 isslanted or angled in a direction generally aligned with the direction ofthe air pulse that emits from the valves 703, 704. In this embodiment,the wall 720 is angled relative to the base plate 712 between 10 and 80degrees, for example, about 30-70 degrees. In this embodiment, the wall720 further includes a splitter panel 722. The splitter panel 722divides the open volume 724 defined by the wall 720 into a first volume726 and a second volume 727. In general, the first valve 703 will pulseinto the first volume 726, while the second valve 704 will pulse intothe second volume 727. The valves 703, 704 may pulse simultaneously inthis embodiment.

In the embodiment of FIGS. 35-40, the accumulator 716 further includes ahandle 730. In the embodiment depicted, the handle 730 extends orprojects from an end wall 732 of the wall 720 of the hood 718. Thehandle 730 is sized to receive at least portions of a human hand so thatthe accumulator 716 can be grasped and easily manipulated.

K. The Embodiment of FIGS. 41-44

Another embodiment of an accumulator 856 is shown in FIGS. 41-44, theaccumulator 856 being an alternative embodiment to accumulator 656,shown in FIGS. 29-34 for use in arrangement 600. The description of allelements of arrangement 600 is incorporated herein by reference.

Accumulator 856 is oriented to retain a pulse of gas over the downstreamaxial end 681 of the media pack 680. In the embodiment shown,accumulator 856 includes a hood 858 that is secured to a base plate 822.It should be understood that by the term “secured to” it is meant thatthe base plate 822 and the hood 858 can be made from the same piece ofmaterial and be formed and bent into the appropriate desired structure.By “secured to” it is also meant that the base plate 822 and hood 858can be fixed to each other with fastening mechanisms, such as welding.Additionally, base plate 822 is configured with thumb screws 828 thatextend through the base plate 822 for connecting accumulator 856 toholder 604 and/or tube sheet 628.

In the embodiment shown, the base plate 822 has an opening 824, whilethe hood 858 includes a shroud section 860 that extends around and abovethe opening 824. The hood 858 also includes a throat section 862 and ascoop section 863 that define an open mouth 864. The open mouth 864receives the jet of gas pulsed from the pulsing arrangement emittedthrough the blow pipes 640.

The throat section 862 has a diameter D₁ and a length L₁ wherein thethroat section is spaced away from the base plate 822 by a distance, L₂.In this embodiment, there is advantage in an arrangement in whichdiameter D₁ ranges from about 0.5 to about 1.25 times the width offilter element 632, and is shown as being 0.9 times the width of filterelement 632. Length L₁ can range from 0 to about 1 times the diameterD₁, and is shown as being about 0.08 times the width of filter element632. Length L₂ can range from 0 to about 2.0 times the diameter D₁, andis shown as being about 0.2 times the diameter D₁.

The throat section 862 and the scoop section 863 are oriented such thattheir common central axis X₁ is at an angle α₁ with respect to thegeneral plane of base plate 822. Angle α₁ can range from 0 degrees toabout 85 degrees, and is shown as being about 37 degrees. Additionally,in particular embodiment illustrated, scoop section 863 has afrustoconical shape that expands in the direction extending away frombase plate 822, at an angle α₂ relative to central axis X₁. Angle α₂ canrange from 0 to about 15 degrees, and is shown as being about 5 degrees.The expanding shape of scoop section 863 allows for advantage, in thatit allows for primary air flowing through the filter to undergo gradualexpansion, thereby allowing for beneficial pressure regain. The scoopsection 863 also acts as a convergence section for the pulse air flow.Although this expanding shape is beneficial, it is not required for thesatisfactory operation of the accumulator 856. Further, as shown inFIGS. 43 and 44, the hood 858 of accumulator 856 may be configuredwithout the scoop section 863.

L. The Embodiment of FIGS. 45-47 g

Another embodiment of an accumulator 956 is shown in FIGS. 45-47 g, theaccumulator 956 being an alternative embodiment to accumulator 656,shown in FIGS. 29-34 for use in arrangement 600. The description of allelements of arrangement 600 is incorporated herein by reference.

Accumulator 956 is oriented to retain a pulse of gas over the downstreamaxial end 681 of the media pack 680. In the embodiment shown,accumulator 956 includes a hood 958 that is secured to a base plate 922.It should be understood that by the term “secured to” it is meant thatbase plate 922 and the hood 958 can be made from the same piece ofmaterial and be formed and bent into the appropriate desired structure.“Secured to” can also mean that base plate 922 and hood 958 are fixed toeach other with fastening mechanisms, such as welding. Additionally,base plate 922 can be configured with thumb screws (not shown) thatextend through the base plate 922 for connecting accumulator 956 toholder 604 and/or tube sheet 628.

In the embodiment shown, the base plate 922 has an opening 924 and thehood 958 includes a shroud section 960 that extends around and above theopening 924. The hood 958 also includes diverging section 962 andconverging section 963 that together form a region of full flow for boththe primary and pulse flows. Additionally, an open bell mouth 964 isconnected to the converging section 963 on the end opposite thediverging section 962. The open bell mouth 964 receives the jet of gaspulsed from the pulsing arrangement emitted through the blow pipes 640and also discharges the primary air flow from the filter. Although bellmouth 964 is not required, bell mouth 964 has a shape that forms abeneficial low entry pressure loss function for the pulse airflow.

In the embodiment shown, the diverging section 962 has a length L₁ and acentral axis X₁. Length L₁ is determined by first cross-sectional areaA₁, discussed later. As shown, length L₁ is 0.95 times A₁ and can rangefrom about 0.25 to about 2.0 times A₁. Additionally, diverging section962 is oriented such that its central axis X₁ is at an angle α₁ withrespect to the general plane of base plate 822. Angle α₁ can range from0 degrees to about 85 degrees, and is shown as being about 45 degrees.

In the embodiment shown, converging section 963 has a length L₂ and acentral axis X₂. Length L₂ is determined by first cross-sectional areaA₁, discussed later. As shown, length L₂ is 0.6 times A₁ and can rangefrom about 0.25 to about 2.0 times A₁. Additionally, converging section963 is oriented such that its central axis X₂ is at an angle α₂ withrespect to central axis X₁. Angle α₂ can range from 0 degrees to about85 degrees, and is shown as being about 13 degrees. In general theangles of the diverging and the converging sections, α₁ and α₂, aremanaged depending on the location of the pulse jet nozzle exhaust 640and distance to the distance to the open mouth 964.

With reference to FIGS. 47a-47d , various cross-sections of hood 958 areshown, as referenced by the lettered cross-section identifiers on FIG.47. By managing the cross-sectional areas as they progress through thehood 958 a converging-diverging enclosed volume region can be createdwhich improves the pulse cleaning of the filter element 632 at lowerpressures for the compressed air supply. This configuration allows thefilter element 632 to operate for longer periods of time at loweroperating pressures. This design can be fabricated, such as by stamping,from metals and from several processes utilizing plastics.

In the embodiment shown, converging section 963 has a first diameter D₁and a corresponding first cross-sectional area A₁, shown at FIG. 47a ,and corresponding to section V-V shown on FIG. 47. First cross-sectionalarea A₁ defines the maximum inlet/outlet diameter and is proportional tothe width of the filter element 632. First diameter D₁ can range fromabout 0.25 to about 1.25 times the width of the filter element 632 andis shown at about 0.7 times the width of the filter element 632.Converging section 963 and diverging section 962 also share a secondcross-sectional area A₂, shown at FIG. 47b , and corresponding tosection W-W on FIG. 47. Second cross-sectional area A₂ is the smallestarea cross-section that the full airflow of both the primary and pulseair flows will pass. Second cross-sectional area A₂ is determinedaccording to first cross-sectional area A₁ and can range from about 0.25to about 0.99 times A₁. As shown, A₂ is about 0.8 times A₁. Also,diverging section 962 and shroud section 960 share a thirdcross-sectional area A₃, shown at FIG. 47d , and corresponding tosection Y-Y on FIG. 47. Area A₃, which is determined according to firstcross-sectional area A₁, can range from about 1 to about 1.5 times A₁.As shown, A₃ is about 1.2 times A₁.

With reference to FIGS. 47e-47g , three additional cross-sectional viewsof shroud portion 960 are shown, as referenced by the letteredcross-section indications on FIG. 47. FIGS. 47e, 47f and 47g showfourth, fifth and sixth cross-sectional areas A₄, A₅ and A₆, all ofwhich are determined according to first cross-sectional area A₁. Asshown, fourth cross-sectional area A₄ is about 1.2 times A₁ and canrange from about 1 to about 1.5 times A₁. Fifth cross-sectional area A₅is shown at about 0.8 times A₁ and can range from about 1 to about 0.5times A₁. Finally, sixth cross-sectional area A₆ is shown at about 0.6times A₁ and can range from about 1 to about 0.25 times A₁.

The above includes example principles. Many embodiments can be madebased on these principles.

1. A method of servicing a dust collector; the dust collector includinga housing having an inlet, a dirty air volume, a clean air volume, atube sheet separating the dirty air volume and the clean air volume, atleast one filter element sealed within the tube sheet, a clean airoutlet, and a air direction arrangement; the method including: (a)removing a first filter element from the tube sheet in the housing; and(b) sealing a second filter element against the tube sheet by orientingat least one projection extending from a plane of the tube sheet into achannel defined by a gasket member secured to the second filter elementand exerting an axial force against the gasket member to form a sealbetween the gasket member and the tube sheet.
 2. A method according toclaim 1 wherein the step of sealing includes orienting the second filterelement to align the at least one projection with the channel defined bythe gasket member such that media in the second filter element isaligned for receiving a pulse jet through a downstream side of thesecond filter element.
 3. A method according to claim 1 wherein the stepof exerting an axial force against the gasket member includes using afilter element retainer including a base plate defining an openingexposing the second filter element; and a fastener arrangementselectively connected to the tube sheet; the fastener arrangementexerting the axial force against the base plate and the gasket member toform a seal between and against the gasket member and the tube sheet. 4.A method according to claim 3 wherein the step of using a filter elementretainer includes using a filter element retainer having a hood securedto the base plate; the hood including a wall extending above the openingin the base plate; the wall having an end secured to the base plate anddefining an open mouth.
 5. A filter element comprising: (a) aracetrack-shaped media pack having first and second opposite axial endsto provide straight through filter flow and a side extending between thefirst and second axial ends; (i) the media pack having first and secondopposite flow faces with a plurality of flutes, each of the fluteshaving an upstream portion adjacent to the first flow face and adownstream portion adjacent to second flow face, selected ones of theflutes being open at the upstream portion and closed at the downstreamportion, while selected ones of the flutes are closed at the upstreamportion and open at the downstream portion; (b) a gasket member securedto the side of the media pack; the gasket member including first andsecond gasket regions separated by a channel; the first gasket regionbeing nearer the media pack than the second gasket region; (i) thegasket member including a first axial area adjacent to the first flowface of the media pack; (A) the first axial area sloping downward andaway from the first flow face of the media pack; (ii) the first gasketregion including an attachment surface secured to the side of the mediapack and a first channel surface from the attachment surface; (iii) thesecond gasket region includes a second channel surface toward the firstchannel surface; the second gasket region having an outer angledsurface; the second channel surface meeting the outer angled surface atan apex; (iv) the first and second channel surfaces having a basetherebetween; and (v) the first channel surface, second channel surface,and base defining the channel; the channel being an open volume betweenthe first and second gasket regions.
 6. A filter element according toclaim 5 wherein the first axial area is a straight surface.
 7. A filterelement according to claim 5, wherein the outer angled surface slopesfrom the apex and outward and toward the first axial area.
 8. A filterelement according to claim 5 wherein: (a) the second gasket region hasan end tip opposite of the first axial area; and (b) and end of theattachment surface of the first gasket region is axially closer to thesecond flow face than the end tip of the second gasket region.
 9. Afilter element according to claim 5 wherein: (a) the channel includes:(i) a length of at least 0.3 inch as measured from an end of one of thefirst and second gasket regions; and (ii) a width of at least 0.15 inchas measured between the first and second gasket regions.
 10. A filterelement according to claim 5 wherein the attachment surface of the firstgasket region is an over-mold securing the gasket member and the side ofthe media pack.